The program pulls from the headlines, a combination of similar cases across the country. The aftermath of the actual shooting death of a black teenager by a Chicago cop changed history, and changed the script.

In 2014, Laquan McDonald was fatally shot by Officer Jason Van Dyke. Initially, Van Dyke was not charged because he claimed McDonald, who was 17, had been behaving erratically, had a small knife and was a threat to the officer.

There was dashcam video of the shooting, but it took a judge’s order 13 months later to get the city to release it. The video showed McDonald veering away from officers, contradicting Van Dyke’s account that he had lunged at him with a knife.

In October 2018, a jury found Van Dyke guilty of second-degree murder and 16 counts of aggravated battery with a firearm — one count for each bullet fired at McDonald. He became the first Chicago cop in decades to be convicted of murder for an on-duty shooting.

McDonald was convicted during the filming for “The Red Line”; his sentencing didn’t change the story or the idea that officers are held to a different standard, but it meant precedence for their fictional officer to face repercussions for his actions.

Showrunners Caitlin Parrish and Erica Weiss, who have worked together for more than 15 years, created the series from their 2011 play “A Twist of Water,” which debuted at a Chicago theater before moving to off-Broadway.

“We returned to those characters and that story that we loved so much,” Weiss told the Daily News. “The cultural conversation and sociopolitical conversation was different between 2011 and 2015 when we wrote the pilot and even more in 2019.”

Parrish and Weiss, both white, built diversity into the writers’ room and crew.

“From moment one, we made it a priority to listen,” Parrish told The News. “We care more about getting the show right than either of us being right."

In the first two episodes provided to critics, “The Red Line” is a heartbreaking reminder that a story doesn’t end when an Emergency Room doctor declares time of death or a trial ends. Family members are left reeling; police officers struggle to move on.

“I was so moved by the immensity of the tragedy,” Wyle, returning to network TV for the first time since “ER,” told The News. “I’m really attracted to characters who go along almost on autopilot and everything that defines them...is stripped away. Where does that leave them?”

“The Red Line” looks at what happens next.

Wyle’s character Daniel grapples with his emotions while dealing with his daughter’s new reality, while Jira (Royale), who grew up with two fathers in a mixed-race household, is looking for something to hold onto. She picks her birth mother.

“She’s trying so hard to get Daniel to understand,” Royale, a relative newcomer to TV, told The News. “She knows her upbringing and she’s thankful for it, but clearly there’s this whole universe she never knew about. She needs someone who looks like her, a woman who looks like her, to get a a better understanding of herself, a better comprehension of what happened to Harrison.”

And for Paul Evans, the white officer who shot and killed the innocent black man, a young cop searches for the truth of that night: colleagues, including his partner, have repeatedly told him he did everything right. But that’s not what happened.

“It exists in the gray,” Fisher, known best for his role on “Shameless,” told The News. “From the moment that he understands what happens, he’s utterly devastated and questioning himself from that point on.”

“The Red Line” is more questions than answers, more doubt than faith. The show doesn’t want you to pick a side or a villain, to blame the white cop for shooting or the black man for being in the wrong place at the wrong time.

“It’s so easy to ascribe a value judgement to something that you’re hearing the top level detail to,” Wyle told The News. “What we do and why we do things is infinitely more than that.”

“The Red Line” premieres Sunday at 8 p.m. on CBS and will air two-hour installments for four consecutive Sundays.